How many significant figures does $0.0730$ have?
Explanation: Identify the non-zero digits and any zeros between them. These are all significant. $0.0{73}0$ Leading zeros are not significant. $\color{orange}{0.0}{73}0$ Since there is a decimal, trailing zeros are significant. $\color{orange}{0.0}{730}$ Counting all the significant digits gives us 3.